Stoker construction



Aug. 25, 1936. 'w HANNA I 2,051,850

STOKER CONSTRUCT ION Original Filed April 5, 1929 I s sheets-sham 1 INVENTOR WILLIAM 'lT-lon sou HANNA BY% 7M v m ATTORNEYS Aug. 25, 1936. w. T.'HANNA STOKER CONSTRUCTION Original Filed April 5, 1929 3 Sheets-Sheet 2 lNVENTO R- WILLIAM THOMPSON HANNA a 76m kl ,7

. ATTORNEYS A 3 Sheets-Shed I5 R m o m mH E w W .A i M L ii H a? .74; v v ATTORNEYS Aqg. 25, 1936. r w. T. HANNA STOKER CONSTRUCTION Original Filed April 5, 1929 III Patented Aug. 25, 1936 UNITED STATES PATENT OFFICE" Original application April 5, 1929, Serial No. 352,760. Divided and this application May 25,

1931, Serial No. 539,745

1 Claim.

This invention relates to stokers in general and particularly to stokers adapted for use on locomotives and the like.

One of the objects of the invention is to provide a simple, compact and sturdy stoker mechanism which will efiectively convey the fuel from a supply bin or hopper to the fire box and advantaneously distribute it therein.

Another object is to provide free movement of the fuel throughout the stoker mechanism.

Other objects include the preventing of jamming as the fuel enters the feeding and preparing mechanism, the reduction of back pressure upon the rising column of fuel and the providing of an advantageous form of conduit construction.

The invention accordingly consists in the features of construction, combinations of elements and arrangements of parts which will be exemplified in the mechanism hereinafter described and the scope of the application of which will be indicated in the following claim.

This application is a division of my co-pending application Serial No. 352,760 filed April 5, 1929 for Stoker construction.

In the accompanying drawings is shown one of the various possible embodiments of the invention in which:

Fig. 1 is a side elevation partially in section.

Fig. 2 is an enlarged longitudinal sectional view of the portion of the stoker mechanism adjacent the fire box but with the preparing and feeding devices removed from the housing.

Fig. 3 is a sectional view on the line 3--3 of Fig. 2.

Fig. 4 is a sectional view on the line 4-4 of Fig. 2.

Fig. 5 is a partially diagrammatic end view of one of the fuel preparing and feeding devices.

Fig. 6 is a transverse view on the line 66 of Fig. 2.

Referring to the drawings, l represents the back head of a locomotive fire box having the usual grate bars H and firing opening I2. Embracing this opening and rigidly mounted on the outer face of the back head is a fuel supply housing l3 which carries, at its lower end, an extension M. This extension encompasses the delivery end of a transfer conveyer l which is rotatively supported in a cylindrical conduit IS. The forward end of the conduit I6 is provided with a universal connection with the extension I4 below the deck I! of the locomotive. This connection comprises a member l6a secured to the end of the conduit l6 as by welding or the like and shaped to fit within the spherical shaped recess I l-a in the end of the extension M, to form a semi-ball and socket joint between the conduit l6 and the extension M.

The conveyer l5 has an operative connection 5' (not shown) with a conveyer 38 mounted for ro tation within the tender hopper l9 below the tender deck 29. The conveyer l8 in turn is operatively connected with a power device 2|, lo- I cated on the locomotive and this connection com- 0 prises a telescopic shaft 22, universally connected at 23 with the power device and at 24 with a shaft 25. This shaft 25 is journaled upon the tender hopper and has-at its rear end a gear (not shown) which meshes with a gear 26 secured to the rear end of the conveyer l8.

The contour of the housing l3 and its extension I4 is designed to properly receive the fuel from the delivery end of the conveyer l5, and to elevate and deliver it to the preparing and feeding mechanism. This mechanism may be of any suitable character but in the present embodiment comprises two rotary vanes or worms 2? and 28 suitably journaled in cap-plates 29 and 38, forming part of the wall of the said housing. In either case, rotary motion is imparted to the vanes or screws 2? and 28 through suitable gearing (not shown) within the housing 3| and driven by the telescopic shafts 32 each of which is universally connected at one end with such gearing and at the other end with the power device 2|, or in any other manner that may be found most expedient.

With reference to Figure 6, although the crosssection of the housing extension 14, and also that 35 part of the housing i3 adjacent thereto, is preferably approximately circular in any cross-section taken perpendicular to its axis, as shown in Figure 6, that portion of the conduit l4 immediately adjacent the transfer conduit It has an oval 40 cross-section, the upper fuel guiding surface of the conduit l4 being oifset above the upper fuel guiding surface of the transfer conduit I6, but the lower surfaces of the two conduits being confluent. With this arrangement thefuel is released from pressure on the top side of the column immediately upon the commencing of its upward path, Furthermore, the cross-sectional dimension of the conduit forward and upward from the point l4-b has an increasing diameter and this also assists in the more efiicient elevating of the fuel to the feeding devices.

As the fuel enters the housing l3 more or less in the form of a column, it encounters the spiral vanes or worms 2! and 28 and these act to break up such column and loosen or prepare the fuel for passage through the firing opening l2. The portion of the wall of the housing immediately below each of the vanes 21 and 28 forms a fuel supporting member in the form of a concave ledge as 33 the surface of which is substantially parallel to an imaginary conically shaped surface containing the periphery of the corresponding vane, but said ledge being arranged eccentric with the axis of said vane (Fig. 5) so that when fuel has once entered between the hub of the vane and the ledge, it will readily .pass on without jamming.

At the junction of the conduit portion of the housing I3 with the housing portion there are formed edges 33a which act as a spillway over which a portion of the sides of the rising column of fuel may pass onto the ledges 33 and into the paths of the outer portions or ends of the spiral vanes 27 and 28. The effect of this spilling over of the sides of the rising column of coal is to decrease its tendency to mound or pile up at the center in front of the vanes and thus reduce the back pressure upon the rising column of coal caused by an excessive mound thereof resting upon the top of the column in a more or less dormant state.

The fuel preparing and feeding device, comprises the rotary vanes or worms 21 and 28. A blast chamber 34 and a distributing plate 35 lie within the firing opening !2 of the locomotive fire box, and these serve to scatter the fuel received from the rotary vanes 21 and 28 efiiciently to all parts of the fire-bed.

In the operation of this stoker mechanism, the coal passes through the floor or deck 20 of the bin or tender into the trough of the hopper l9 and is moved therein by means of the conveyer I 8 to a suitable crushing structure 36 whereby the abnormally large lumps of fuel are cracked and broken up to normal size before discharge from the hopper. The fuel is then delivered to the transfer conveyer l5 by which it is transported and delivered into the ascending conduit formed by the housing extension 14 and the lower portion of the housing l3. Therein it is elevated to the rotary preparing vanes or feeders 21 and 28, which serve to subsequently advance the fuel into the firing opening above the level of the fire and cause it to fall upon and flow over the blast chamber 34. This action tends to further loosen it and prepare it for reception by the distributor plate 35 from which it is scattered over the fire by means of blasts of steam emitting from the jets of the blast chamber.

It will be recognized that the form of the passage through which the fuel is elevated to the preparing and feeding device is such, particularly at the top of the said passage on the right hand and left hand sides, that the rising column of fuel is permitted to spill over into the path of the outer ends or portions of the spiral vanes and the effect of this is to decrease the tendency of the fuel to mound or pile up at the center in front of such vanes as might otherwise occur with certain conditions of fuel. Furthermore, it is evident that the curvature of the ledge 33, being arranged substantially eccentric with the axis of the rotating vanes, enables lumps of fuel to readily pass without becoming wedged between the hub portions of the vanes and the ledge.

It will thus be seen that there is provided a construction of an essentially practical nature in which the several objects of the invention are attained.

While I have shown and described a particular construction embodying the novel features of the invention, it is to be understood that the same is for illustration only and it will be obvious that the construction and arrangement of parts may be variously modified and altered without departing from the spirit and scope of the invention as set forth in the appended claim.

I claim:

In a locomotive stoker for transferring fuel forwardly from a source of fuel to a fire box of a locomotive, in combination, a conduit for transferring fuel from the source of supply to the fire box comprising a horizontal transfer section for guiding the fuel forwardly in a substantially horizontal path and an elevating section continuing from the forward end of the horizontal section for guiding the fuel in a path having a relatively large upward component to the fire box, the cross-section of the-fuel-guiding surface of the horizontal section being substantially circular,-

and the cross-section of the fuel-guiding surface of that portion of the elevating section adjoining the horizontal section being oval (its long axis vertical) and enclosing a larger area than that enclosed by the cross-section of the horizontal section, the lower portions of the fuel-guiding surfaces of said oval section and horizontal section being confluent but the upper portion of the fuel-guiding surface of the oval; section being offset above the fuel-guiding surface of the horizontal section so that the column of fuel passing from the horizontal section to the elevating section is suddenly released from pressure at the top at the moment the path of the fuel acquires a relatively large upward component.

WILLIAM THOMPSON HANNA. 

